Summer Time Sadness: A Tale of "Brain-Eating Amoeba"

Abstract

Every year during summer, warm fresh water reservoirs poses a reclusive threat to public health. This almost universally fatal disease (95-99% mortality) known as ‘Primary Amebic Meningoencephalitis (PAM)’ or ‘Amebic Encephalitis’ which is caused by a thermophile ameboflagellate, Naegleria fowleri aka ‘Brain-eating amoeba’.1–3 Due to low incidence rate, the dangers of this ‘Summertime Sadness’ are underestimated and ignored. In past few years, number of cases worldwide has increased significantly due to global climate change, particularly ‘El Nino’ effect is playing major role. The Naegleria fowleri is a climate-sensitive which enters through nose either during swimming or performing ‘neti’ (nasal rinse) and ablution, a ritual cleansing that includes nasal passages.2 This has been now confirmed that city water supply through household faucets also contain Naegleria fowleri and pose more significant health concerns. In cold water, this ameboflagellate remains in dormant form as a cyst which transform into infective flagellate form when water becomes warm. Once enter through nasal mucosa, the Naegleria fowleri migrates to the brain via the olfactory nerve and cause lethal neuro-inflammation and damage to the brain. Whether Naegleria can enter through the open wounds is not known. However, one cannot get infected with Naegleria from swallowing contaminated water.3 Historically, the very first existence of brain-eating ameba was reported in Ireland, in 1909. Later, in 1965, two physicians named, R.F. Carter and M. Fowler from Australia, formally studied and identified the Naegleria fowleri as a causative agent of PAM.1 In 1978, CDC created the national Free-living Ameba (FLA) Laboratory, which has become a national resource and global leader for providing diagnostic and clinical guidance as disease is rare. The CDC began formally tracking Naegleria fowleri infections since 1989.2